That isn't possible. What is the context? There may be other solutions.
Well, I was hoping to keep it under wraps, but I guess I have to.
When Badspot set the avatar object in the Avatar_Preview GUI, he did not name it, and he had every function after that search for the null object.
Had he named it, I could apply a hat object to it; and proceed with the rest of my add-on.
Replacing the object with a named object turns up errors since all the functions search for a null object.
Strangely enough; unlike the rest of the functions that search for the null object,
ObjectView.mountObject(name, model, skin, parentName, nodeName, lod)
This code does not work if it does not have a name, and in-fact CRASHES the game.
Avatar_Preview.mountObject("ROCKETL","Add-Ons/Weapon_Rocket_Launcher/rocketlauncher.dts","","","head",100);
I have tested this on the named object as well, and it works flawlessly.